• Preheat your oven to 300° Fahrenheit.
• Pat the short ribs dry with paper towels, and season them generously with kosher salt and black pepper.
• Let them rest on a baking rack for 30 minutes.
• Heat olive oil in a large Dutch oven over medium-high heat.
• Lightly dust both sides of the ribs with all-purpose flour. Once the oil is hot, add the beef short ribs and sear them for a few minutes on each side.
• Remove the ribs from the pot and set aside.
• Add the onions, celery, and carrots to the pot with a pinch of salt and pepper. Sauté until tender, about 10 minutes.
• Add minced garlic, beef base, and tomato paste to the pot. Stir well and sauté for an additional 1-2 minutes.
• Pour in the red wine vinegar, deglazing by scraping the browned bits from the pot bottom.
• Pour in the beef broth and return the short ribs to the pot, adding rosemary, thyme, and bay leaves.
• Bring the liquid to a low simmer. Cover the pot and transfer it to the oven.

Cook to Tenderness

• Braise for 3 to 3½ hours, or until the ribs are tender and falling off the bone.
• Remove the meat and vegetables from the Dutch oven and place them on a platter.
• Skim fat from the braising liquid and discard the bay leaves, rosemary, and thyme.
• Bring the liquid to a boil. Mix cornstarch with water until smooth and stir into the liquid until thickened, about 2-3 minutes.
• Pour the sauce over the short ribs or serve it on the side. Adjust seasonings as needed and savor your meal.